Year: 2001
Type: article
Abstract: The spherical spin model with infinite-range ferromagnetic interactions is investigated analytically in the framework of nonextensive thermostatics generalizing the Boltzmann-Gibbs statistical mechanics. We show that for repulsive correlations, a weak-ferromagnetic phase develops. There is a tricritical point separating para-, weak-ferro, and ferro regimes. The transition from paramagnetic to weak-ferromagnetic phase is an unusual first-order phase transition in which a discontinuity of the averaged order parameter appears, even for finite number of spins. This result puts in a different way the question of the stability of critical phenomena with respect to the long-ranged correlations.
Institutions: Université Paris-Sud, Centre National de la Recherche Scientifique, Laboratoire de physique des Solides, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Institut National de Physique Nucléaire et de Physique des Particules, Grand Accélérateur National d'Ions Lourds, Instituto Venezolano de Investigaciones Científicas
Language: English
Subfield: Statistical and Nonlinear Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2076309304